Sampling apparatus



June 26, 1951 J. c. sToKEs SAMPLING APPARATUS Filed Dec. 15, 1948 3 Sheets-Sheet 1 Jo/7n C. Jip/res [Nl/EN Tof? 5) a ATTORNEYS J. c. s'roKEs 2,557,925

SAMPLING APPARATUS June 26, 1951 Filed Dec. 15, 1948 3 SheetsShet 3 dp. UM Mm 59 l ONU r /I QWL/Mf I 38 v ATTORNEYJ Patented June 26, 1951 TENT OFFICE SAMPLING APPARATUS John C. Stokes, Houston, Tex., assigner to Reed Roller Bit Company, Houston, Tex., a corporation of riexas Application December 13, 1948, Serial No. 64,925

10 Claims. (Cl. Z55-1.4)

l This invention relates to new and useful improvements in sampling apparatus.

The invention relates particularly to improved apparatus for obtaining fluid and core samples under the natural formation pressure from hard to permit recovery of the samples without removal of the drill pipe; the `apparatus having means for coupling the same within the drill bit and also having a core bit at its lower end, whereby when in position within the stem, the apparatus may be rotated to assure cutting of a core sample in relatively harder sub-surface formations.

A particular object of the invention is to provide an improved sampling apparatus, of the character described, wherein a rotatable core bit and core-receiving tube for cutting and retaining a core are combined with a iiuid sample chamber which is arranged to recover a fluid sample under the natural formation pressure, whereby simultaneous recovery of the core and uid may be effected.

Still another object of the invention is to provide an improved sampling apparatus, of the character described, wherein the core-receiving tube having the core bit at the lower end is formed with means on its external surface for packing or sealing oliF around said tube, whereby a luid sample under natural formation pressure may be recovered through said tube.

A further object of the invention is to provide an improved sampling apparatus having a sealing means at the upper portion of its core-receiving tube whereby after a core has been out, the reduced bore formed by the cutting of the core is closed or sealed at its upper end to permit a true and accurate huid sample to be obtained from the formation therebelow; the closure or sealing of the bore being accomplished by a, nexible sealing element or by an enlargement on the upper portion of the core-receiving tube.

Still another object of the invention is to provide an improved core-receiving tube having a continuous spiral or helical projection or rib on its outer surface which normally functions to remove the cuttings from the reduced bore formed by the coring operation, but which acts to retain said cuttings to form a pack-01T or seal around the tube when the upper end of the bore is closed just prior to completion of the coring operation and taking of the fluid sample.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a, reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

Figure 1 is a longitudinal, sectional View of a sampling apparatus, constructed in accordance with the invention, and illustrating the same mounted in position within a drill pipe,

Figure 2 is an enlarged longitudinal sectional view of the lower portion of the sampling apparatus,

Figure 3 is a horizontal, cross-sectional view, taken on the line 3--3 of Figure 2,

Figure 4 is a View, similar to Figure 2, ofa modified form of the invention,

Figure 5 is a horizontal, cross-sectional view, taken on the line 5 5 of Figure 4,

Figure 6 is a horizontal, cross-sectional view, taken on the line 3 6 of Figure 4,

Figure 7 is a detail view of the release valve employed with the form shown in Figure 6, and

Figure 8 is a view, partly in section and partly in elevation of still another form of the invention.

In the drawings, the numeral l@ designates a drill pipe or stem which has an elongated drill collar I! connected. to its lower rend by the usual pin and box connection. A drill bit I 2 is connected to the lower end of the drill collar and is providedwith the usual cutting blades. As is usual practice, the bore IllaJ of the drill pipe communicates with the axial bore lla of the drill collar, whereby the drilling uid may be circulated downwardly therethrough. The drill bit is formed with an axial bore i4 which is in communication with the bore of the drill collar and in the upper enlarged portion of the bore of the bit, a landing ring l5 is mounted. The particular construction of the bit l2 is subject to variation, it being preferable to employ any of the well known types of bits now in general use. The improved sampling apparatus is generally indicated lat A and is illustrated as combined with an inner assembly B, such as is shown and described in my co-pending application, Serial No. 54,665, filed October 15, 1948, now Patent No. 2,528,981. This inner assembly comprises an upper cylinder i6 which is connected by a pin il to a latching device I8, the latter including a pivoted latch element I9 adapted to engage a slot formed in the lower portion of a collar 2i mounted within the lower end of the drill pipe. The latching device I8 functions to rotatably connect the drill pipe Iii with the inner cylinder I5.

The lower end of the cylinder is connected with a coupling 22 and a piston rod 25 extends through the bore of the coupling with its upper end disposed within the bore I'I. The upper end of the rod carries an operating piston 2li. The coupling 22 is connected by means of a shear pin 25 with the piston rod and thus, the latching mechanism and cylinder IS are connected to the piston rod through said shear pin. A protective sleeve 26 surrounds the operating piston 24. Pressure within the drill pipe and drill collar is conducted to the under side of the operating piston 2@ through ports 2, but it is apparent that when the shear pin is connecting the coupling to the piston rod 23, upward movement of the operating piston is prevented.

A lower cylinder 28 has its upper end connected. to the coupling and has the piston rod 23 extending axially therethrough. This lower cylinder has an annular projection or shoulder 29 on its external surface which is adapted to seat on the landing ring I5. A piston 35 is secured to the lower end of the piston rod 23 and when the operating piston 24 is moved upwardly within the upper cylinder I6, the lower piston 3! moves upwardly within its cylinder. A ball check valve 3l is mounted within the lower inlet end of the lower cylinder 28 and is downwardly seating upon an annular valve seat 32.

When the shear pin 25 is connecting the coupling 22 to the piston rod 23, the pistons 2l! and 30 are in their lower position as illustrated in Figure 1. When the pin 25 is fractured, the hydrostatic pressure of the fluid within the drill pipe may act throughout ports 2? against the underside of the piston 2A to move said piston upwardly within its cylinder i6. This results in an upward movement of the lower piston 3Q whereby a suction is created at the inlet end of the lower cylinder 25 to draw a uid sample into the interior of the cylinder which forms a fluid receiving chamber.

As has been pointed out, the arrangement of the pistons 24 and 35, together with their associate parts, are fully disclosed in my co-pending application, Serial No. 54,665, and the details of construction of this unit form no part of the present invention. So long as a sample receiving chamber is provided, the present invention may be carried out.

The sampling apparatus generally indicated at A comprises a core receiving tube 33 having an axial bore 34 extending entirely therethrough with the upper end of the tube coupled to the lower end of the lower cylinder 2li, by a suitable coupling sleeve 35. As illustrated in Figure 2, the upper end of the bore 34 of the tube may be reduced as indicated at 3ft-a. Throughout the major portion of its surface and extending from the lower end thereof, the core receiving tube 33 is formed with a continuous spiral or helical projection or rib 36 which terminates adjacent an annular external shoulder SI provided nearer the upper end of the tube. Suitable core, Cutters 33 are provided at the lower end of the core tube and a split ring core catcher 39 is mounted within the lower end of the bore of said tube.

A flexible annular packing sleeve til encircles the upper end of the tube 33 and is supported upon the external shoulder or projection 3l, the external diameter of this sleeve being preferably substantially of the same diameter as the helical projection or rib. A suitable wire re-eniorcing cage ll may be associated with the packing sleeve 45 and the bore d'2 oi said sleeve is inclined outwardly whereby fluid may enter the upper end of the sleeve to urge the same radially outwardly. It will be evident that the provision of the spiral or helical projection or rib vforms a helical or spiral groove 36a which extends from the lower end of the core receiving tube 33 to the packing element.

In the operation of the apparatus, the assembly A is connected to the lower end of the lower cylinder 28 by the coupling member 35 and the complete apparatus may be lowered as by pumping downwardly through the drill pipe lll to the position shown in Figure l. In such position, the latching device ill latches the apparatus within the lower portion of the drill pipe, and at this time the shear pin 25 is connecting the latching device 4B, upper cylinder IE and coupling 22 to the piston rod. Since the lower cylinder 28 is connected to the coupling, the upper and lower pistons are locked against upward movement within their respective cylinders.

Rotation of the drill pipe I6 will impart a rotation through the latching device I8 and cylinders it and 28 to the core receiving tube 33. As the tube rotates, the core drilling cutters 38 will cut a small bore C in the bottom of the main well bore D and the core 5i) will pass upwardly into the bore 3d of the tube in the usual manner. During the coring operation, the cuttings will travel upwardly through the spiral space 35a formed by the continuous helical projection or rib and will be carried upwardly into the main well bore D to be circulated out in the usual manner by the drilling uid.

The coring operation will continue until the packing sleeve d6 at the upper end of the core receiving tube 33 enters the small bore C and when this occurs, the sleeve will function to substantially close the upper end of the bore. A continued coring operation after the sleeve enters the bore will restrict the escape of cuttings through the helical space 36a and said cuttings will nrmly pack within the space 36a to seal against the wall of the smaller bore. The upper end of the packing sleeve is exposed tothe pressure of the uid within the main well bore and this fluid entering the tapered bore 42 of said sleeve will function to expand said sleeve into sealing engagement with the wall of the small bore C to assure an efficient seal at the upper end of said bore.

When this seal has been effected, rotation oi the drill stem is halted and the weight of the drill pipe I is imposed upon the apparatus through the device I8. This weight is su'icient to shear the pin 25 which has locked the pistons 24 and 3U in their lowered position. As soon as the pin 25 is sheared, the hydrostatic pressure of the huid column may act against the operating piston 24 to move said piston upwardly Within its cylinder I6, and obviously, as the operating piston moves upwardly the lower piston 3B is also moved upwardly within its cylinder 28. This creates a suction which draws the fluid or gas under its natural formation pressure from the sub-surface forma.- tion, suchv fluid entering the bore of the tube 33 through the space around the core and then flowing upwardly past the check valve 3| which has been unseated by the suction of the piston 33. The iiuid is thus drawn upwardly into the lower end of the cylinder 28 and upon the piston 30 completing its movement, the check valve 3l is again reseated to trap the fluid sample within the lower cylinder.

A wire line or cable may then be lowered through the drill pipe and engaged with the latching device to retrieve the apparatus consisting of the assemblies A and B, and obviously, the core catcher 39 will function to retain the core 53 within the bore of the tube 33. Upon retrieving of the apparatus, it is possible to recover the actual core sample 33, which is within the tube 33. In order to recover the fluid sample, the coupling sleeve 35 is disconnected from the lower end of the lower cylinder 38 and a suitable valve device, such as disclosed in my co-pending application above referred to, may be utilized to remove the fluid sample from the cylinder 28.

From the foregoing, it will be seen that a simple and eiiicient apparatus for simultaneously recovering a core and a fluid sample under formation pressure is provided. The arrangement of the spiral or helical projection on the core tube makes it possible to utilize the cuttings as a means of efficiently packing of the small bore to assure recovery of the iiuid sample under actual sub-surface formation pressures. The flexible packing sleeve 4Q will, of course, be acted upon by the hydrostatic fluid pressure of .the drilling fluid which is present in the main well bore D, this fluid entering the upper end of the packing sleeve to expand or urge the same radially outwardly into tight sealing position.

It might be desirable in some instances to cause the core 5i) to move upwardly into the lower cylinder 22 along with the uid sample, and in such instance, the arrangement illustrated in Figures 4-'7 will be employed. In this event, the core tube 33 is of the same construction as illustrated in Figure 1 and the only change in the apparatus is an elimination of the ball check valve 3l and the substitution of a iap valve 5i. The ap valve is pivotally mounted Within a tubular housing 52 which has its lower end connected to the core receiving tube 33 with its upper end connected through a coupling 53 with the lower end of the cylinder. The bore 52a of the housing 52 as well as the bore 53a of the coupling 53 are of the same or larger diameter than the bore 34 of the core receiving tube. The flap valve 5l closes the upper end of the bore of the core tube and is urged to a closed position by a spring arm 54.

This form of the invention operates in substantially the same manner as the form shown in Figure 2 with the coring operation being carried out by a rotation of the core tube. After the core 59 has entered the core receiving tube and the seal has been provided by the packing sleeve it in conjunction with the cuttings packed within the spiral space 35a, the shear pin 25 is fractured to permit operation of the pistons 24 and 30. As the piston 33 moves upwardly within the lower cylinder 28, the suction created thereby pulls the flap valve 5i to an open position and draws the core upwardly into the lower cylinder at the same time that it sucks or draws the fluid sample from the sub-surface formation. Thus, in this form of the invention, the core as well as the fluid sample are drawn into the lower cylinder 28 and are recovered when said cylindefl is brought to the surface. In removing the sample from the form of the invention shown in Figure (i, the valve housing 52 is provided with a spring pressed check valve 55 which is mounted within a radial opening 55 in the wall of the housing. A plug 51 normally closes the opening 56 and as is clearly shown in Figure 4, the check valve 55 opens inwardly. To obtain the sample, a releasing tool 58 (Figure 7) is employed, and this tool comprises a housing 59 which is adapted to be threaded into the opening 55 in place of the plug 5l. A manually actuated valve opening stem @ii is mounted in the housing 59 and has a pin 5i at its inner end adapted to engage and unseat the check valve 55. A suitable escape line 62 is threaded into the opening so that when the check valve is opened, the fluid sample within the cylinder 28 may be conducted through the line 62 to a suitable container. It is noted that the check valve 55 is mounted above the flap valve 5l so that said hap valve may remain seated while the fluid sample is recovered from the cylinder 23.

Although it is desirable to employ the flexible packing sleeve lic for packing orf the upper end of the bore C, it is not necessary that this type of seal be used, and in Figure 8, a modified arrangement is illustrated. In this instance, the upper end of the core receiving tube 33 is formed with a fiared or tapered portion 53, which portion. has its upper end a diameter larger than the small bore C which is drilled during the coring operation. As the core tube in this form of the invention outs a core, the upper tapered portion B3 will enter the upper end of the bore C to substantially close said bore. This results in the cuttings from the core bit 38 iirmly packing below the Vtapered portion and within the spiral space 35a. to eiectively seal off between the core tube and the bore C. Obviously, after the seal is effected, the suction piston 3i! may be operated as above described and a fluid sample under natural formation pressure may be drawn into the lower cylinder or sample receiving chamber 28. It is evident that either the ball check valve 3| or the nap valve 5i may be used with the form of the invention shown in Figure 8. Actually, the only difference between the modification of Figure 8 and the forms shown in Figures 2 and 4 is the substitution of a tapered portion at the upper end of a core receiving tube for the flexible packing sleeve.

rfhe foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, Without departing from the spirit of the invention.

Having described the invention, I claim:

l. The combination with a drill stem, of a sampling apparatus including, a tubular core receiving element having a core bit at its lower end and adapted to be rotatably connected with the drill stem, whereby said element and bit may be rotated to drill a bore and thereby out a core which enters said element, means on the exterior of the. tubular element and co-acting with the wall of the bore which is cut by the core bit for confining cuttings removed from the formation by the core bit between said element and bore to pack off therebetween, and a fluid samplereceiving chamber above the element and in communication with the bore thereof, whereby after packing off between the element and bore has 7 been effected, a fluid sample may be taken through the tubular element and into the samplereceiving chamber.

2. The combination as set forth in claim l, wherein the means for confining the drill cuttings comprises a spiral or helical projection extending throughout the major portion of the external surface of the tubular element whereby a helical space is formed by the said projection, together with an enlargement on the tubular element immediately adjacent the upper end of the helical projection.

3. The combination with a drill stem of a sampling apparatus extending therethrough including, a cylinder forming a fluid sample-receiving chamber, means for rotatably connecting the cylinder to the drill stem whereby a rotation may be imparted thereto, a tubular core receiving element connected to the lower end of the cylinder and having its bore communicating with the bore of the cylinder, core cutting means on the lower end of the tubular element whereby rotation of said element drills a bore in the formation and thereby cuts a core which enters the tubular element, and means on the exterior of the tubular element (zo-acting with the Wall of the bore drilled by the core cutting means for conning drill euttings between the tubular element and the bore to seal off therebetween whereby iiuid sample may be taken through the tubular element and into the sample-receiving cylinder.

Il. The combination as set forth in claim 3, wherein the means for conning the drill cuttings is a continuous helical rib formed on the exterior surface of the tubular element and extending from the lower end thereof to a point terminating short of the upper end thereof, together with an enlargement on the tubular element adjacent the upper end of the helical rib.

5. The combination with a drill stem of a sampling apparatus extending therethrough including, a cylinder forming a fluid sample-receiving chamber, means for rotatably connecting the cylinder to the drill stein whereby a rotation may be imparted thereto, a tubular core receiving element connected to the lower end of the cylinder and having its bore communicating with the bore of the cylinder, core cutting means on the lower end of the tubular element whereby rotation of said element drills a bore in the formation and thereby cuts a core which enters the tubular element, an enlargement at the upper end of the tubular element of a diameter larger than the external diameter of said element and adapted to enter the bore to close the upper end thereof after the tubular element has penetrated the formation, and a continuous helical rib on the exterior of the element forming a helical space between the lower end of said element and the enlargement, said helical rib functioning to carry the drill cutsings upwardly from the bore during the coring operation and before the enlargement enters said bore and functioning to trap or confine the cuttings after the enlargement enters said bore to seal off between the element and bore to permit a uid sample to be taken through the element and conducted into the uid receiving chamber.

6. The combination as set forth in claim 5, wherein the means on the upper end of the tubular element for closing the bore is a flexible packing element which is arranged to be expanded by pressure from above.

7. The combination as set forth in claim 5, wherein the enlargement on the upper end of the tubular element is a pressure actuated packing element.

8. A sampling apparatus including, a core receiving tube having an axial bore and having a core cutting means on its lower end, an enlargement comprising fiexible sealing means at the upper end of the element, and a helical continuous projection on the external surface of said element and extending trom the lower end thereof to a point adjacent the enlargement at its upper end.

9; A sampling apparatus including, a core receiving tube, an annular packing sleeve mounted on the upper end of said tube and adapted to be expanded radially outwardly from pressure thereabove, and a continuous spiral projection on the exterior of the tube extending from the lower end oi said tube to a point adjacent the lower end of the annular packing sleeve.

l0. The combination with a drill stem of a sampling apparatus extending therethrough ineluding, a cylinder forming a fluid sample-receiving chamber, means for rotatably connecting the cylinder to the drill stem whereby a rotation may be imparted thereto, a tubular core receiving element-connected to the lower end of the cylinder and having its bore communicating with the bore of the cylinder, core cutting means on the lower end of the tubular element whereby rotation of said element drills a bore in the formation and thereby cuts a core which enters the tubular element, means on the exterior of the tubular element for coniining drill cuttings between the tubular element and the bore to seal off therebetween whereby a iiuid sample may be taken through the tubular element and into the samplereceiving cylinder, a piston within the fluid receiving cylinder, with said piston being actuated by the hydrostatic fluid pressure within the drill stem, and means for normally holding the piston against operation so that said piston is not actuated until after a seal has been eiected between the exterior of the tubular core receiving element and its bore.

JOHN C. STOKES.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 801,853 Cowell Oct. 1'7, 1905 2,214,551 Edwards Sept. 10, 1940 2,418,500 Chambers Apr. 8, 1947 2,528,981 Stokes Nov. 7, 1950 

